1. Technical Field
This invention relates to a coiler for strip metal comprising a rotatably mounted drivable coiler shaft and a hollow reel, non-rotatably connected to the coiler shaft and contains an expanding mechanism, which is operable by an actuator and comprising radially adjustable pressure-applying members, protruding through apertures in the reel to engage the coil.
2. Description of the Prior Art
Coilers having an expanding mandrel have the advantage that a non-positive coupling which is sufficient for the coiling of a strip can be established between the expanding segments of the expanding mandrel and the coil so that the disadvantages involved in the introduction of the leading end of the strip into a receiving slot are avoided. These disadvantages reside in that the coiler shaft must be arrested, the strip may be pinched as the reel is raised, and the leading end of the strip is reversely bent.
On the other hand, coilers comprising an expanding mandrel involve a relatively complex structure and their load-carrying capacity is restricted. For this reason, coilers having no expanding mandrel are used for hot strip because the heat from the hot strip which may be at temperatures between 180.degree. and 1200.degree. C., reduces the load-carrying capacity of such expanding mandrels. This applies not only to expanding mandrels having expanding segments but also for expanding mandrels which comprise a hollow reel, connected to the coiler shaft and radially adjustable pressure-applying members, movable through the reel into engagement with the coil (U.S. Pat. No. 4,254,920). In these coilers, the pressure-applying members for establishing a non-positive coupling to the coil are held in slide tracks and are separated by actuating wedges, which are axially slidably mounted in the hollow coiler shaft. During the coiling of hot strip, all these structural parts are subjected not only to a mechanical load but also to a high heat load. For this reason these known coilers cannot be used to coil hot strip.